The button states could easily be read by using an Arduino’s analog input. A Pro Mini model was chosen for its small size as it could be housed in the radio compartment of the dash.

The keypad uses an onboard ATMega328P to scan the matrix for button presses, decode them, and send them via UART or I²C to an Arduino. [ELECTRONOOBS] has the PCB files available via Patreon for ...

Running out of GPIO pins? Learn how to connect multiple buttons to just one Arduino pin using clever wiring and resistor techniques. Perfect for compact projects, keyboards, or when using small ...